Apparatus for installing bushings

ABSTRACT

Apparatus for seating a bushing includes a member which centers a bar coaxially in an aperture in a part and a disk the edge of which is recessed on one side thereof so as to engage one end and the adjacent portion of the inner wall of the bushing, the edge of the other end of said bushing being initially engaged with the edge of the aperture on one side of the part. A second centrally apertured disk abuts the other side of the part, and the bar extends through the aperture in this disk and through apertures in a ram and pressure cylinder assembly. The free end of the ram engages the second disk and the bar is locked to the pressure cylinder so that when pressure inside the latter is increased, both the bar and cylinder move away from the second disk and the bushing is thereby pulled into the aperture in the part.

United States Patent Shiflet [15] 3,654,685 [451 Apr. 11,1972

3,044,157 7/1962 3,107,417 10/1963 Jaquish, Jr. et al. 3,245,138

APPARATUS FOR INSTALLING BUSI-HNGS Robert H. Shiflet, Chula Vista, Calif.

Rohr Corporation, Chula Vista, Calif.

Mar. 16, 1970 Inventor:

Assignee:

Filed:

Appl. No.:

References Cited UNITED STATES PATENTS Fink ..29/252 X 4/1966 De Wilde 3,359,618 12/1967 Murphy ..29/200 D Primary Examiner--Thomas H. Eager Attorney-George E. Pearson [5 7] ABSTRACT Apparatus for seating a bushing includes a member which centers a bar coaxially in an aperture in a part and a disk the edge of which is recessed on one side thereof so as to engage one end and the adjacent portion of the inner wall of the bushing, the edge of the other end of said bushing being initially engaged with the edge of the aperture on one side of the part. A second centrally apertured disk abuts the other side of the part, and the bar extends through the aperture in this disk and through apertures in a ram and pressure cylinder assembly. The free end of the ram engages the second disk and the bar is locked to the pressure cylinder so that when pressure inside the latter is increased, both the bar and cylinder move away from the second disk and the bushing is thereby pulled into the aperture in the part.

9 Claims, 3 Drawing Figures PATENTEBAPR 11 I91? 3, 654, 685

. SHEET 1 OF 2 INVENTOR.

ROBERT H. SHIFLET APPARATUS FOR INSTALLING BUSI-[INGS SUMMARY OF THE INVENTION This invention relates to manufacturing apparatus and, more particularly, to apparatus for installing bushings in various parts under a press fit.

In the manufacture of aircraft components and other products, it is necessary to seal cylindrical bushings in apertures in parts of difierent types with great precision, since even small misalignments of such bushings can make expensive machined parts unacceptable for their intended use. The apparatus disclosed herein provides an efl'ective means for installing bushings in precisely coaxial relation in apertures, and in addition apparatus in accordance with the invention is relatively inexpensive, easy to use, and light in weight so that it can readily be moved to different locations where parts must be assembled.

In accordance with the invention a bushing is initially positioned so that the outer edge of one end thereof engages an edge of the aperture in a part. A centrally apertured disk having a recessed edge on one side thereof is placed against the other end of the bushing, with the flat, annular surface of the recessed edge of the disk abutting the end surface of the bushing and the side of the cylindrical projection defined on the disk by said recessed edge engaging the inner wall of the bushing. A bar having an enlarged diameter at one end thereof is inserted through the aperture in the aforesaid disk, and the shoulder defined at the enlarged diameter end of said bar is engaged with the side of said disk remote from the part. The bar fits'snugly in the aperture in the disk and thus it is coaxial with the bushing, the cylindrical portion of the disk being coaxial with said disk aperture. In one form of the invention the bar is slidably disposed in an aperture which extends coaxially through a cylindrical member which in turn is slidably disposed within the aperture in the part, and the bar projects from the outer side of this member and through a hole in a second disk which abuts the side of the part remote from the bushing. In another form of the invention the bar is slidably disposed in an aperture which extends coaxially through a member having a cylindrical portion which is slidably disposed in the aperture in the part and an integral portion which engages the side of said part remote from said bushing. Each of these arrangements serves to maintain the bar in coaxial relation with the aperture in the part. In each embodiment the bar projects outwardly from its centering member and passes through an aperture extending between the ends of a ram mounted in an annular pressure cylinder, the bar also passing through the central aperture in said cylinder and through a washer and a nut which limit movement of the cylinder relative to the bar in the direction away from the part. The free end of the ram abuts the second disk, and thus when the cylinder is pressurized it moves away from said disk, which pulls the bar in the same direction and draws the bushing into the aperture in the part. Preferably the pressure applied to the cylinder (and thus to the ram associated therewith) is adjustable to a predetermined level, thereby eliminating the possibility of damage either to the bushing or the part in which it is installed.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view taken along the common longitudinal axis of components of a preferred embodiment of the invention.

FIG. 2 is another sectional view of the same embodiment, illustrating a different position of certain components thereof.

FIG. 3 is a schematic representation of apparatus which may be used to pressurize a hydraulic cylinder of the same embodiment.

DETAILED DESCRIPTION In FIGS. 1 and 2 reference number designates generally a part having an aperture 12 extending therethrough, the longitudinal axis of the aperture being perpendicular to the parallel sides 14, 16 of the part. Designated generally by reference number 18 is a bushing comprising a tubular portion 20 which can be forced into aperture 12 under a press fit and a lip 22 which projects laterally from said tubular portion at one end thereof. FIG. 1 illustrates the position of bushing 18 when it is ready to be installed in aperture 12 by means of the apparatus to be described, in which initial position of the bushing the outer edge of its tubular portion engages the edge of said aperture on one side of part 10.

Apparatus in accordance with the invention comprises a bushing centering member which is designated generally by reference number 24 and preferably is in the form of an apertured disk having an annular recess circumscribing one edge thereof. Thus bushing centering member 24 comprises a flat surface 26 which engages the end of the bushing 18 remote from part 10, and a cylindrical portion 28 which projects from said flat surface and fits snugly within the aperture 30 in bushing 18. The aperture 32 which extends through bushing centering member 24 is coaxial with the cylindrical portion 28 of said member.

Extending across aperture 12 on the side of part 10 remote from bushing 18 is a ram support member which is designated generally by reference number 34 and which also preferably is in the form of an apertured disk. More particularly, the aperture which extends through ram support member 34 comprises: a first middle portion 36 having a minimum diameter; a second portion 38 disposed next to said first portion 36 on the side thereof adjacent the ram support member and having substantially the same diameter as aperture 12 in part 10; a third portion 40 which extends from said second portion 38 to the adjacent end surface 42 of the ram support member and which has an increased diameter; and a fourth portion 44 which extends from said first portion 36 to the other end surface 46 of the ram support member and which is sized to snugly receive one end of a component to be described. All portions of the aperture in ram support member 34 are coaxial, and said third portion 40 defines one edge of the flat annular surface 42 which engages side 16 are part 10 circumscribes the aperture 12 in said part. The end surfaces 42 and 46 of the ram support member are perpendicular to the longitudinal axis of the aperture therein.

Reference number 48 designates generally a ring comprising a larger diameter portion 50 which is slidably disposed in the aperture in part 10 and the end of which is seated in portion 38 of the aperture in ram support member 34, and a smaller diameter portion 52 which projects from said portion 50 toward bushing 18. The aperture in ring 48 is coaxial with the aperture in part 10 and comprises a smaller diameter portion 54 and a larger diameter portion 56.

Generally designated by reference number 58 is a housing having a tubular outer wall 60 and a tubular inner wall 62 concentric with said outer wall, a wall 64 which extends between said inner and outer walls at one end thereof, and a flange 66 which projects radially inward from outer wall 60 at the opposite end of the housing. An annular ram is designated generally by reference number 68 and comprises a tubular wall 70 which is slidably disposed in the aperture 72 in housing 58, a flange 74 which projects radially inward from said wall 70 at the end of the ram which projects from housing 58, and a section 76 which extends laterally from the other end of wall 70 and the sides of which respectively slidably engage the facing surfaces of walls 60 and 62. The free end of ram 68 fits snugly in portion 44 of the aperture in rarn support member 34, and the aperture 78 in said free end has substantially the same diameter as portion 36 of said aperture in member 34 and is coaxial therewith. One end of a conduit 80 is attached to Wall 60 of housing 58 and communicates with the space 82 between portion 76 of ram 68 and wall 64 of the housing through a hole 84 in said wall 60. The other end of conduit is connected to the pressurizing apparatus represented in diagrammatic form in FIG. 3. More specifically, the other end of conduit 80 is connected to a pressure gage designated generally by reference number 86, a second conduit 88 extends from this gage to a third conduit 90 the ends of which are respectively connected to an air-operated hydraulic pump 92 and an adjustable pressure relief valve 94, a fourth conduit 96 is connected at its ends to said relief valve and pump, and an air hose 98 is connected to said pump.

Lastly, a draw bar is designated generally in FIGS. 1 and 2 by reference number and comprises: a head 102 one side of which abuts the outer end surface of bushing centering member 24; a first cylindrical portion 104 which is slidably disposed in aperture 32 in said member 24 and portion 56 of the aperture in ring 48; a second cylindrical portion 106 which is coaxial with said first portion 104 and slidably disposed in portion 54 of the ring aperture, and which extends in spaced relation through portion 36 of the aperture in ram support member 34, through the aperture 78 in the free end of ram 68, and through the aperture defined by wall 62 of housing 58; and a threaded end portion 108 which projects from the end of housing 58 remote from said ram support member. A washer 110 is disposed around the projecting end of draw bar 100 and abuts end wall 64, and a nut 112 is engaged with the draw bar and abuts the washer. Thus ring 48 serves as a means for maintaining the draw bar in coaxial relation with aperture 12 in part 10, and washer 110 and 112 serve as means for limiting movement of housing 58 relative to said draw bar in the direction away from said part.

OPERATION The manner in which the above-described apparatus is used to install the tubular portion of bushing 18 in aperture 12 of part 10 is as follows. The outer edge of the small diameter end of the bushing is first engaged with an edge of aperture 12 as illustrated in FIG. 1, and bushing centering member 24 is positioned on the other end of the bushing as illustrated in the same drawing. Ring 48 is inserted into aperture 12 from the side 16 of part 10 opposite bushing 18, the large diameter end of the ring being seated in portion 38 of the aperture in ram support member 34 and the ram support member being placed against said side 16. The free end of ram 68 is inserted into portion 44 of the aperture in the ram support member with the ram initially retracted into housing 58. Draw bar 100 is then inserted through the apertures in bushing centering member 24, ring 48, ram support member 34, ram 68, and wall 62 of housing 58, and washer 110 and nut 1 12 are engaged with the end of the draw bar which projects from the housing. Pressure relief valve 94 is adjusted so that the pressure exerted by pump 92 on the hydraulic fluid 114 in housing 58 and conduits 80 and 88 will not exceed a predetermined level, any excess pressure being bled off through the relief valve and conduit 96. Gage 86 indicates the pressure applied to housing 58 and ram 68. Compressed air is then admitted to pump 92 through hose 98, thereby pressurizing the fluid between end wall 64 of housing 58 and portion 76 of ram 68 and causing said housing to move away from ram support member 34 and to the position illustrated in FIG. 2. As the housing moves away from the ram support member it of course pulls draw bar 100 in the same direction, and thus bushing 18 is simultaneously drawn into aperture 12 in part 10. The pressure which is applied to ram 68 is limited to that which will not damage the lip 22 of the bushing when it is seated against side 14 of part 10, and preferably the pressurizing apparatus is provided with sensing means which relieve the pressure applied to the ram as soon as the bushing is seated. Because of the arrangement of the components of the disclosed apparatus, bushing 18 is held in coaxial relation with aperture 12 as it is drawn thereinto, thereby eliminating the misalignment of the bushing relative to the aperture and the resultant damage to the bushing and part which often results from the conventional installation methods which employ arbor presses and the like. After the bushing has been installed, nut 112 is removed from draw bar 100 so that the other components of the apparatus can be disengaged from the bushing and part 10.

It will be obvious that various modifications can be made in the disclosed embodiment of the invention without departing from the principles of its construction. For example, ring 48 and ram support member 34 can be joined at their abutting surfaces. Hence the scope of the invention should be considered to be limited only by terms of the appended claims.

I claim:

1. Apparatus for installing a bushing in an aperture extending through a part, comprising:

a bushing centering member having a flat surface engaged with an end of said bushing, the outer edge of the other end of said bushing initially engaging an edge of the aperture in said part, said bushing centering member having a cylindrical portion which projects from said flat surface and fits snugly within the aperture in said bushing;

a ram support member extending across the aperture in said part and engaging the side of said part remote from said bushing, an aperture extending through said ram support member in substantially coaxial relation with the aperture in said part;

a draw bar extending through the apertures in said bushing, part, and ram support member and engaged at one end thereof to said bushing centering member so that when it is moved axially of said apertures toward said ram support member said bushing centering member is pulled in the same direction, said draw bar projecting from the side of said ram support member remote from said part;

a closed tubular housing disposed on the side of said ram support member remote from said part and an annular ram mounted in said housing and extensible from one end thereof by pressure applied therein, the free end of said ram engaging the side of said ram support member remote from said part, said draw bar extending through the aperture in said ram and being connected to said housing so that when the latter is moved away from said ram support member said draw bar is pulled in the same direction;

draw bar centering means disposed within the portion of the aperture in said part which is adjacent said ram support member and adapted to maintain said draw bar in coaxial relation with said aperture; and

means for pressurizing said housing to thereby extend said ram from said one end thereof.

2. Apparatus as defined in claim 1 wherein said draw bar centering means comprises a ring slidably disposed in the aperture in said part, said draw bar being slidably disposed in the aperture in said ring.

3. Apparatus as defined in claim 1 wherein said draw bar centering means comprises a cylindrical portion of said ram support member which projects from the side thereof adjacent said part and which is slidably disposed in said aperture therein, the aperture in said ram support member extending through said cylindrical portion and said draw bar being slidably disposed therein.

4. Apparatus as defined in claim 1 wherein said housing is annular and the aperture therein is coaxial with the aperture in said ram, said draw bar extending through the aperture in said housing and projecting from the end of said housing remote from said ram support member, and including means on said projecting end of said draw bar for limiting movement of said housing relative thereto.

5. Apparatus as defined in claim 1 wherein said bushing centering member is annular and said draw bar extends through the aperture therein, and including means on said draw bar for limiting movement of said bushing centering member relative thereto.

6. Apparatus as defined in claim 1 including means for limiting the pressure applied within said housing by said pressurizing means.

7. Apparatus for installing a bushing in an aperture extending through a part, comprising:

an annular bushing centering member the peripheral portion of one side of which engages an end of said bushing,

the outer edge of the other end of said bushing initially engaging an edge of the aperture in said part, said bushing centering member having a cylindrical portion which projects from said one side thereof and fits snugly within the aperture in said bushing, the aperture in said bushing centering member being coaxial with the side of said cylindrical portion;

an annular ram support member extending across the aperture in said part and the peripheral portion of one side of which engages the side of said part remote from said bushing, the aperture in said ram support member being substantially coaxial with the aperture in said part;

a draw bar extending through the apertures in said bushing a closed tubular housing disposed on the side of said ram support member remote from said part and an annular ram mounted in said housing and extensible from one end thereof by pressure applied therein, the free end of said ram engaging the side of said ram support member remote from said part, said draw bar extending through the apertures in said ram and housing, projecting from the end of the latter remote from said ram support member, and having thereon means for limiting movement of said housing relative thereto, whereby when said housing is moved away from said ram support member said draw bar is pulled in the same direction;

draw bar centering means disposed within the portion of the aperture in said part which is adjacent said ram support member and adapted to maintain said draw bar in coaxial relation with said aperture;

a pump operatively connected to said housing for applying pressure therein to thereby extend said ram from said one end thereof; and

means for limiting the pressure applied within said housing by said pump.

8. Apparatus as defined in claim 7 wherein said draw bar centering means comprises a ring slidably disposed in the aperture in said part, said draw bar being slidably disposed in the aperture in said ring.

9. Apparatus as defined in claim 7 wherein said draw bar centering means comprises a cylindrical portion of said ram support member which projects from the side thereof adjacent said part and which is slidably disposed in said aperture therein, the aperture in said ram support member extending through said cylindrical portion and said draw bar being slidably disposed therein. 

1. Apparatus for installing a bushing in an aperture extending through a part, comprising: a bushing centering member having a flat surface engaged with an end of said bushing, the outer edge of the other end of said bushing initially engaging an edge of the aperture in said part, said bushing centering member having a cylindrical portion which projects from said flat surface and fits snugly within the aperture in said bushing; a ram support member extending across the aperture in said part and engaging the side of said part remote from said bushing, an aperture extending through said ram support member in substantially coaxial relation with the aperture in said part; a draw bar extending through the apertures in said bushing, part, and ram support member and engaged at one end thereof to said bushing centering member so that when it is moved axially of said apertures toward said ram support member said bushing centering member is pulled in the same direction, said draw bar projecting from the side of said ram support member remote from said part; a closed tubular housing disposed on the side of said ram support member remote from said part and an annular ram mounted in said housing and extensible from one end thereof by pressure applied therein, the free end of said ram engaging the side of said ram support member remote from said part, said draw bar extending through the aperture in said ram and being connected to said housing so that when the latter is moved away from said ram support member said draw bar is pulled in the same direction; draw bar centering means disposed within the portion of the aperture in said part which is adjacent said ram support member and adapted to maintain said draw bar in coaxial relation with said aperture; and means for pressurizing said housing to thereby extend said ram from said one end thereof.
 2. Apparatus as defined in claim 1 wherein said draw bar centering means compRises a ring slidably disposed in the aperture in said part, said draw bar being slidably disposed in the aperture in said ring.
 3. Apparatus as defined in claim 1 wherein said draw bar centering means comprises a cylindrical portion of said ram support member which projects from the side thereof adjacent said part and which is slidably disposed in said aperture therein, the aperture in said ram support member extending through said cylindrical portion and said draw bar being slidably disposed therein.
 4. Apparatus as defined in claim 1 wherein said housing is annular and the aperture therein is coaxial with the aperture in said ram, said draw bar extending through the aperture in said housing and projecting from the end of said housing remote from said ram support member, and including means on said projecting end of said draw bar for limiting movement of said housing relative thereto.
 5. Apparatus as defined in claim 1 wherein said bushing centering member is annular and said draw bar extends through the aperture therein, and including means on said draw bar for limiting movement of said bushing centering member relative thereto.
 6. Apparatus as defined in claim 1 including means for limiting the pressure applied within said housing by said pressurizing means.
 7. Apparatus for installing a bushing in an aperture extending through a part, comprising: an annular bushing centering member the peripheral portion of one side of which engages an end of said bushing, the outer edge of the other end of said bushing initially engaging an edge of the aperture in said part, said bushing centering member having a cylindrical portion which projects from said one side thereof and fits snugly within the aperture in said bushing, the aperture in said bushing centering member being coaxial with the side of said cylindrical portion; an annular ram support member extending across the aperture in said part and the peripheral portion of one side of which engages the side of said part remote from said bushing, the aperture in said ram support member being substantially coaxial with the aperture in said part; a draw bar extending through the apertures in said bushing centering member, bushing, part, and ram support member, one end of said draw bar projecting from the side of said bushing centering member remote from said part and having thereon means for limiting movement of said bushing centering member relative thereto, whereby when said draw bar is moved axially of said apertures toward said ram support member said bushing centering member is pulled in the same direction, said draw bar also projecting from the side of said ram support member remote from said part; a closed tubular housing disposed on the side of said ram support member remote from said part and an annular ram mounted in said housing and extensible from one end thereof by pressure applied therein, the free end of said ram engaging the side of said ram support member remote from said part, said draw bar extending through the apertures in said ram and housing, projecting from the end of the latter remote from said ram support member, and having thereon means for limiting movement of said housing relative thereto, whereby when said housing is moved away from said ram support member said draw bar is pulled in the same direction; draw bar centering means disposed within the portion of the aperture in said part which is adjacent said ram support member and adapted to maintain said draw bar in coaxial relation with said aperture; a pump operatively connected to said housing for applying pressure therein to thereby extend said ram from said one end thereof; and means for limiting the pressure applied within said housing by said pump.
 8. Apparatus as defined in claim 7 wherein said draw bar centering means comprises a ring slidably disposed in the aperture in said part, said draw bar being slidably disposed in the aperture in said ring.
 9. Apparatus as defined in claim 7 wherein saId draw bar centering means comprises a cylindrical portion of said ram support member which projects from the side thereof adjacent said part and which is slidably disposed in said aperture therein, the aperture in said ram support member extending through said cylindrical portion and said draw bar being slidably disposed therein. 